// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements.  See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License.  You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package internal

import (
	"sort"

	"github.com/apache/dubbo-kubernetes/pkg/bufman/pkg/stringutil"
)

// VersionSpec specifies the rules, ids, and categories for a given version.
type VersionSpec struct {
	RuleBuilders      []*RuleBuilder
	DefaultCategories []string
	// May include IDs without any categories.
	// To get all categories, use AllCategoriesForVersionSpec.
	IDToCategories map[string][]string
}

// AllCategoriesForVersionSpec returns all categories for the VersionSpec.
//
// Sorted by category priority.
func AllCategoriesForVersionSpec(versionSpec *VersionSpec) []string {
	categoriesMap := make(map[string]struct{})
	for _, categories := range versionSpec.IDToCategories {
		for _, category := range categories {
			categoriesMap[category] = struct{}{}
		}
	}
	categories := stringutil.MapToSlice(categoriesMap)
	sort.Slice(
		categories,
		func(i int, j int) bool {
			return categoryLess(categories[i], categories[j])
		},
	)
	return categories
}

// AllIDsForVersionSpec returns all ids for the VersionSpec.
//
// Sorted lexographically.
func AllIDsForVersionSpec(versionSpec *VersionSpec) []string {
	m := make(map[string]struct{})
	for id := range versionSpec.IDToCategories {
		m[id] = struct{}{}
	}
	return stringutil.MapToSortedSlice(m)
}

// AllCategoriesAndIDsForVersionSpec returns all categories and rules for the VersionSpec.
//
// Sorted lexographically.
func AllCategoriesAndIDsForVersionSpec(versionSpec *VersionSpec) []string {
	m := make(map[string]struct{})
	for id, categories := range versionSpec.IDToCategories {
		m[id] = struct{}{}
		for _, category := range categories {
			m[category] = struct{}{}
		}
	}
	return stringutil.MapToSortedSlice(m)
}
